The version of kernel installed on the remote host is prior to 4.14.225-121.357. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1487 advisory.

    An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to     the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be     encountered. In one case, an error encountered earlier might be discarded by later processing, resulting     in the caller assuming successful mapping, and hence subsequent operations trying to access space that     wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery     from the error. This affects drivers/block/xen-blkback/blkback.c. (CVE-2021-26930)

    An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI     backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially     being at least under the influence of guests (such as out of memory conditions), it isn't correct to     assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running     in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.
    (CVE-2021-26931)

    An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations     often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success     or failure of each one is reported to the backend driver, and the backend driver then loops over the     results, performing follow-up actions based on the success or failure of each operation. Unfortunately,     when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively     implying their success from the success of related batch elements. In other cases, errors resulting from     one batch element lead to further batch elements not being inspected, and hence successful ones to not be     possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are     vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and     drivers/xen/gntdev.c. (CVE-2021-26932)

    A flaw was found in the way access to sessions and handles was handled in the iSCSI driver in the Linux     kernel. A local user could use this flaw to leak iSCSI transport handle kernel address or end arbitrary     iSCSI connections on the system. (CVE-2021-27363)

    A flaw was found in the Linux kernel. An out-of-bounds read was discovered in the libiscsi module that     could lead to reading kernel memory or a crash. The highest threat from this vulnerability is to data     confidentiality as well as system availability. (CVE-2021-27364)

    A flaw was found in the Linux kernel. A heap buffer overflow in the iSCSI subsystem is triggered by     setting an iSCSI string attribute to a value larger than one page and then trying to read it. The highest     threat from this vulnerability is to data confidentiality and integrity as well as system availability.
    (CVE-2021-27365)

    An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the     netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of     changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior     of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.
    (CVE-2021-28038)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

Amazon Linux AMI : kernel (ALAS-2021-1487)

high Nessus Plugin ID 147919

Version 1.4

Version 1.3

Version 1.4 Dec 12, 2024, 9:55 AM CVSS metrics ("Cvssv4 score" set to 0.0) CVSSv2 severity (based on None, severity decreased from "High" to "Low") Detection (updated detection logic) Plugin metadata Plugin Feed: 202412120955
Version 1.3 Jan 9, 2024, 3:00 PM CVSS temporal metrics ("CVSSv2 temporal vector" set to "CVSS2#E:POC/RL:OF/RC:C". "CVSSv3 temporal vector" set to "CVSS:3.0/E:P/RL:O/RC:C") Exploit attributes ("Exploit available" set to "True". "Exploitability ease" changed from "No known exploits are available" to "Exploits are available") Plugin Feed: 202401091500